Dengue antibodies in Polish travellers returning from the tropics. Evaluation of serological tests.

Dengue is a viral disease caused by an RNA virus of the genus Flavivirus, family Flaviviridae, occurring as four serotypes (DEN-1, -2, -3, -4). It is transmitted to humans by the Aedes mosquitoes, mainly A. aegypti. The occurrence of dengue is strictly related with their preferred breeding areas. Dengue endemic regions are inhabited by some 2.5 billion people. 50-100 million cases of dengue fever and up to 1 million cases of dengue haemorrhagic fever are noted worldwide in more than 100 countries every year. The aim of the reported examinations was to diagnose dengue virus infections in returning travellers. In the years 2006-2009 serological tests were performed in 753 persons. In the diagnostics we used ELISA to find IgM and/or IgG class of antibodies against dengue virus, rapid immunochromatographic (cassette) test, NS1 viral antigen detection by ELISA, and virus RNA detection by RT-PCR method. IgM or IgG class antibodies, and both classes simultaneously, were detected in 19.8% of the examined cases. The greatest number of infections came from India and the Far East, next from South and Central America, and the smallest number from Africa. Sixteen patients with diagnosed dengue, including three cases of dengue haemorrhagic fever, were hospitalized.

Usefulness of PCR method for detection of Leishmania in Poland.

Leishmania parasites are the etiological agents of leishmaniosis, with severe course and often fatal prognosis, and the global number of cases has increased in recent decades. The gold standards for the diagnosis of leishmaniosis are microscopic examinations and culture in vitro of the different clinical specimens. The sensitivity of these methods is insufficient. Recent development in specific and sensitive molecular methods (PCR) allows for detection as well as identification of the parasite species (subspecies). The aim of the study was to estimate the usefulness of molecular methods (PCR) for detection of Leishmania species and consequently for the implementation of such methods in routine diagnostics of leishmaniosis in Polish patients returning from endemic areas of the disease. In our investigations we used 54 known Leishmania positive DNA templates (from culture and clinical specimens) received from the CDC (Atlanta, GA, USA). Moreover, 25 samples of bone marrow, blood or other tissues obtained from 18 Polish individuals suspected of leishmaniosis were also examined. In PCR we used two pairs of primers specific to the conserved region of Leishmania kinetoplast DNA (kDNA) minicircle (13A/13B and F/R). Using these primers we obtained amplicons in all DNA templates from the CDC and in three Polish patients suspected for Leishmania infection. In one sample from among these cases we also obtained positive results with DNA isolated from a blood specimen which was previously negative in microscopic examinations.

Severe malaria--analysis of prognostic symptoms and signs in 169 patients treated in Gdynia in 1991-2005.

In the period 1991-2005, 169 patients with the diagnosis of malaria were hospitalized in the Department of Tropical and Parasitic Diseases, Institute of Maritime and Tropical Medicine in Gdynia (from 2003--the Academic Centre of Maritime and Tropical Medicine, Medical University of Gdansk). All the cases were analysed for severity, occurrence of complications and permanent sequelae of the disease. According to the criteria set by the WHO (5), malaria was classified as severe in 36 cases. All of them were Plasmodium falciparum infections or mixed infections: P. f. and another species of the parasite. Patients in this group developed a number of complications, inter alia shock, acute respiratory distress syndrome (ARDS), acute renal failure, blackwater fever, severe anemia, disseminated intravascular coagulation, myocarditis, consciousness disorders of varied degree, acute transient psychoses, and exacerbation of ischemic heart disease. In one case of a pregnant woman, necrosis of the fetus occurred in the course of disease in the 4th month of pregnancy. Moreover, meningoencephalitis was diagnosed in two patients--in one of them concurrently with symptoms and signs of malaria, while in the other one-3 weeks after the symptoms subsided. In 6 patients, permanent sequelae of the disease developed and in 4 patients the disease was fatal. The cause of death was multi-organ failure, with the first sign of poor prognosis being rapidly progressing renal failure resistant to treatment in three men; in one case death resulted from cerebral malaria. In cases of suspected malaria, relapsing malaria or in mixed infections, molecular testing was a valuable complementary tool of diagnosis, which helped in beginning the appropriate treatment.

Malaria relapse and recrudescence among travellers to the tropics.

This study describes 14 cases of relapse and recrudescence of malaria, treated between 1991 and 2003. In that period, 146 patients were hospitalized in the Clinic of the Institute in Gdynia: 20 women and 126 men. In 103 cases the disease was caused by Plasmodium falciparum, in 31 cases by Plasmodium vivax, in 5 cases by Plasmodium malariae, and in 2 cases by Plasmodium ovale. Five patients were found to have mixed infections, with either P. falciparum and P. vivax or P. falciparum and P. ovale. Relapses in patients previously treated in the country or abroad accounted for 9.6% of all the treated cases of malaria. Recrudescences and relapses were diagnosed of both the tropical malaria (6 cases), and the tertian malaria caused by P. vivax (4 cases). Moreover, in 4 patients diagnosis was made of secondary malaria due to P. vivax infection, while the primary attack was caused by invasion of P. falciparum. Also discussed was the issue of drug-resistance of plasmodia and the resulting problems with the treatment.